Problem with new MacOs

Good day!

Friends brought McBuck Air 11 about two months ago. Without me, they opened and launched and began to use nothing without understanding in McOs. And for the last three weeks, I have been listening that the beech is very hot and noisy and very much slows down. I took it home with the first thought that I had something put or overheated myself or that I … At the first serious launch of programs, it becomes clear that Kernel_task is going crazy and just injects beeches into a stupor.
Today is Sunday … I decided to take everything down and put a clean system. The first three hours were good. Even MS Office delivered iLife … and now iWork and update started a buzz, again kernel_task was foolish.
I read an article about Onyx. Put. On autopilot, something was cleaned … Now I’m waiting … but the very fact: what can be with this kernel_task? I waited, restarted, and only I started moving the mouse, again everything was humming and monitoring of the system showed a full load of the processor.
Is there an idea that the upgrade of the McOs was somehow wrong? I try to put the system again from scratch and prevent it from being updated?
Right now, while I’m writing a post, I restarted the beech in Utility mode and noticed that in this mode it continued to buzz for three minutes after the utility started and calmed down. What causes heating? System or piece of iron?

What can you advise?

P/S : It also overheats very much. Maybe because of work but friends “dressed” poppies in a protective mat with a pattern (like this ). Maybe this does not allow air to circulate?

It’s not possible for anyone here to fully diagnose your problem. If your friends installed things on your computer that you don’t understand, it’s best to reinstall the operating system.

Thank for reply!
I tried! Now the second time I will try to reinstall the system from another resource … I’ll see what happens … But the first two sources were also different

If things are making strange noises and overheating, you may have a hardware problem. Your computer should be under warranty. I’d talk to customer support directly.